Gas-engine muffler



Oct.

F. F. HAMILTCJN GAS ENGINE MUFFLER Filed April 23, .1929

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Patentedv Oct. 7, 1930 UNITED sTATEs PATENT y OFFICE -I'RANCIS E'HAMIIITQN, 0F INDIANAPOLIS,-INDIANA, ABSIGNOB T0 HAMILTON MUF- FLEB COMPANY, OF INDIANAPOLIS, INDIANA GAS-ENGINE MUFFLEB' Application Bied April 23, 1929.- Serial No. 857,467.

This invention relates to means for muffling the exhaust gases from gas engines and Ithe like and has for its primary purposes 'the mufliing of the sound, prevention of back pressure ordinarily encountered in muliling devices heretofore employed, and the provision for permittingv the escape of exhaustv gases very rapidly .from the means ,at extremely high speeds of high powered engines. lo These and other objects will become apparent in thefollowing description of the invention made in reference to the accompanying drawing in whichv Fig. 1 is a side elevation of a Inufller embodying the invention.

Fig. 2, a fragmentary top plan view of the muiiler.

Fig. 8, a transverse section on the line 3 3 2'0 in Fig. 2.

Fig. 4', a modified form of the rear end of the mufller in fragmentary side elevation.-

Like characters of reference indicate like parts throughout the several views in the drawing.

' I form a cylindrical housing 5 having preferably a plurality of spaced apart beads 6 projecting circumferentially therein. The forward or intake end of the housing 5 is enclosed bythe head 7 preferably conical in shape and an intake pipe 8 is passed concentrically through the head 7 axially of the housingv 5. f

The intake pipe 8 extends lfor a substantial distance to within the housing and has its rear endv carried in a cup like depression 9,

Fig. 2, which `depression is formed in the plate 10.l The depression 9, the center of which is on the axis ofthe housing 5, is however, eccentrically located in reference to the plate 10, the platelO having an outer circular periphery over which is fitted the rear lend of the tube 11, the platelO forming a complete closure at the rear end of the tube 11 between that tube and the pipe 8.

By reason ofthe location ofthe depression 9 as fitted over the pipe 8, the plate 10 thereby carries the,tube 11 eccentrically of the pipe 5o 8 so that the pipe 8 is not on the longitudinal axis of the tube 11 but considerably to one side thereof.

Thei tube 11 has a 'plurality of spaced apart beads 12 projecting circumferentially therein, :and the forward end of the tube 11 is completely opened and terminates substantially in the plane of the juncture of the housing 5 with the head 7. The intake pipe 8 is provided with a plurality of holes 13 therethrough, the diameters of which vary fromv a large diameter on thatside of the pipe nearestthe wall of the tube 11 to smaller ,diameters at a distance around therefrom.

A nipple 14 projects rearwardly from the cup 9 and has an internal diameter reduced from that of the pipe 8. A tube 15 has its forward end slidably fitted over the nipple 14 and extends rearwardly therefrom axially of the housing 5.- Spaced back from the forward end of the tube 15 is a collar 16 frustroconical in shape which is fixed to the tube 15 around its smallest diameter and flares outwardly and forwardly from its line of fixation about the tube 15.

A second frustro-conical collar 17 is joined around its forward base end to the periphery -of the base of the collar 1 6 so that the collar`v 17 in reality encloses the collar 16. However, the slope of the collar 17 is less than that o f the collar 16 so that therel is an increasing spacetherebetweenfrom the forward to the rearward ends respectively of the two collars. The collar 17 is perforated by a plurality of spaced apart V slots 18 having their widest openings at the base or forwardend of the collar 17.

The rear end of the collar 17 is united circumferentially therearound to the forward end of the pipe 19, which pipe 19 concentrically encircles the tube 15 and extends rearwardv ly from the collar 17 to pass concentrically through the rear head 20, the head 20 being preferably conical in shape and joining with the housing 5 so as,- to enclose the rear end 95 thereof. K

The annular space between the tube 15 and l I the pipe 19 has a cross sectional area substan'-` tiallyv equal to the cross sectional `area of the intake pipe 8. `100 A third collar v21"1i'kewise frustro-conical in shape has its base secured circumferentially around the bases of the collars 16 and 17,

u vand extends rearwardly and inwardly todown behind the last of the beads 6 but not contacting the wall of the housing 5. A flange-23 is formed on the rear end of the pipe 19 outside of the housing 5 and. at a slight distance back of the head 20 and receives thereagainst the companion flange 24 of a fitting generally designated by the nu-l meral 25, the two flanges being held togetherby othe bolts 26. y Y

The main body of the fitting 25 is hollow and of an internal 'diameter equal to that of the'pipe 19 and has a tailv pipe 26. leading therefrom oil'to one side of the axis` of the fitting. f

VA pipe 27 Ais curved to have its rear end substantially parallel to the rail pipe 26 and enters the fitting 25 angularly from the side and thencecurved around to have-its f orward end positioned axially ofthe fitting to define an annular space therearound and to receive' in a sliding fit thereover the rear end ofthe tube 15. A butterfly valve 28 is positioned in the pipe'27 just outside of its intersection with the fitting 25 and has a vertical shaft 29 extending through the pipe 27 ,as a means of rotating the valvefrom aclosed position as indicated by the solid lines in Fig.l 2 to an open passage as indicated by the dash lines.

Referring now to Fig. 4 a slightly modified structure is there shownin that the fitting 25 is dispensed with and in its place is a short tube 30 of the same internal diameter as that of the pipe 19. A short section of tube 31 is carried concentrically within the tube '30 and is of a diameter to rece-ive therein with a snug fitthe rear end of the tube 15. The `butterfly valve 28 is 'there shown as being mounted within the tube 31, and the tube 31 preferably terminates a short distance from the rear end of thevtube 30 so as `to set up an ejector action when the butterfly valve is open.

In operation,` gases enter through the pipe 8 and the valve 28 is normally closed so that these gases` are discharged through the various openings 13to within the tube 11 from which the gases may discharge therefrom through the forward open end and flow therearound. back within the housing 5 and travel rearwardly over the beads 6,` the for' mation of which causes considerable turbu- 'Y lence of the gases.

By reason of the collar 16 the gases must pass between its periphery and the housing 5 to reach the rear portion of the muilier, where the gases may in part strike the for- Ward side of the collar 22 and be deflected toward the opening under the collar 21 and in part pass around the collar 22 .to Within the space behind it -and in front of the head which the heretofore structuresemplo'yed in muiilers would not stand up or were too noisy for pleasure car use, the valve 28 is opened to permit gases coming into the pipe 8 to l travel in part on through the tube 15 and out through the pipe 27. It is to be noted that the tube 15 is smaller in diameter' than that of the pipe 8 so that the, gases are re stricted in leaving the pipe 8 and entering the tube 15 so that even when the va1ve-28 is open some of the gas entering the pipe 8 will discharge through the openings 13 :and

go through the muffler as above described and discharge from the tail pipe 26. L

Attention is also directed to the fact that the valve 28 is located entirely without the muiier housing or shell 5 and not at some point therewithin.

I claim: Y

1. In a muffler, a housing, front and rear heads, an intake pipe entering and extending a distance Within the housin through the front head, a tube surroun 'ing and spaced from the intake pipe within the housing having an opening at its forward end within the housing and its rear e'nd closed, said intake pipe ohaving openings therethrough discharging within said tube, an exhaust pipe extending from said rear head and discharging'therebehind, ajsecond tube fixed to the rear end of the intake pipe and extending to within said exhaustpipe, and l a valve in saidv second tube, said second tube having itsvrear end removed froml said exhaust pipe back of said rear head, and said l' valvenbeing located in said removed end.

2. In a mulller, a housing, front and rear charging within said tube, an exhaust pipe extending from said rear head discharging therebehind, a second tube fixed to the l rear end of the intake pipe and extending to within said exhaust pipe, and a valve in said second tube, the entrance into said second extending from said` rear head and discharging therebehind, a second tube fixed to the rear end of the intake pipe and extending to within said exhaust pipe, and a valve in said second tube, and said exhaust pipe extending forwardly from said rear head for a distance within said housing.

4. In a muier, a housing, front and rear heads, an intake pipe entering and extending a distance within the housing through the front head, a tube surrounding and spaced from the intake pipe within the housing having an opening at its forward end within the housing and its rear end closed, said intake pipe having openings therethrough discharging within said tube, an exhaust pipe extending from said rear head and discharging therebehind, a second tube fixed to the rear end of the intake pipe and extending to within said exhaust pipe, and a valve in said second tube, and said exhaust pipe extending forwardly from said rear ead for a distance within said housing, and a collar fixed around said second tube forwardly of and spaced from the front end of said exhaust pipe.

5. In a muier, a housing, front and rear heads, an intake pipe entering and extending a distance within the housing through the front head', a tube lsurrounding and spaced from the intake pipe within thehousing having an openingat its forward end within the housing and its rear end closed, said intake pipe having openings therethrough discharging within said tube, an exhaust pipe extending from said rear head and discharging therebehind, a second tube fixed to the rear end of the intake pipe and extending to within said exhaust pipe, and a valve in said second tube, and said exhaust pipe extending forwardly from said rear head for a distance within said housing, and

a collar fixed around said second tube forwardly of and spaced from the front end of said exhaust pipe, and a second collar fixed to the outer periphery of the first collar and extending rearwardly to form an 'annular passageway between its rear end and the exhaust pipe.

6. In a muiiler, a housing, front and rear heads, an intake pipe entering and extending a distance within the housing through the front head, a tube surrounding and spaced from the intake pipe within the housing having an opening at its forward end within the housing and its rear end closed, said intake pipe having openings therethrough dis- "charging within said tube, an exhaust pipe extending from said rear head and dischargingl therebehind, a second tube fixed to the rear end of the intake pipe and extending to within said exhaust pipe, and a valve in said second tube, and said exhaust pipe extending forwardly from said rear head for a distance within said housing, and a collar fixed around said second tube forwardly of and spaced from the front end of said exhaust pipe, and a second collar fixed tothe outer periphery of the first collar and extending rearwardly to form an annular assageway between its rear end and the ex aust pipe, and an intermediate collar fixed between said two collars and the front end of said exhaust pipe having openings therethrough to provide communication to within said exhaust pipe. 7 In a muiiier, a housing, front and rear heads. an intake pipe entering and extending a distance within the housing through the front head, a tube surrounding and spaced from the intake pipe within the housing having an opening at its forward end within the housing and lts rear end closed, said intake pipe having openings therethrough discharging within said tube, an exhaust pipe extendin from said rear head and discha ing there ehind, a second tube fixed to t e rear end of the intake pipe and extending to within said exhaust pipe, and a valve in said second tube, and said exhaust pipe extending forwardly from said rear head for a distance within said housing, said second tube hav'ng a diameter less than that of said intake pipe and that of said exhaust pipe.

In testimony whereof I aix my si ature.

FRANCIS F. HAMIL ON.

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